Simple issue, complex problem...
There are a number of issues here which compound into a very complex problem:
The BBC, ITV, SeeSaw et al are content providers, that is they create the products for consumption by the consumer.
Consumers, pay for the content through one medium or another whether it be the licence fee or having to watch a couple of advertisements.
In the middle are the suppliers. This is the ISPs. The problem they have is that they set them selves up as the deliverers of content just like the tranport firms who deliver goods to shops. The issue they are now finding is that they have insufficient bandwidth (or to keep the analogy, vans or wagons) to deliver the content. They therefore need to buy new vans and money is scarce so like any supplier they can either increase the charges for delivery but that will potentially put consumers and or the content providers off using them and thus they lose business or they look at other ways to increase the value of what they do.
If you look at the big transport companies they go way begond providing just a van to stick things on. The create warehouses to store goods for their customers, they advertise on their assets, etc. ISPs needs to learn from this. Content providers need systems to improve delivery, the iPlayer is rubbish when accessed at peak times as programmes constantly stop while they buffer due to the volume of users, what is needed is a good warehouse a bit closer to users in different parts of the country to store the content and make delivery quicker. There is nothing to stop ISPs providing such a service from adding in some additional advertising of their own into the stream (targetted if the users allow). By doing this they improve their revenue streams without actually increasing base charges.
The problem is that ISPs are telecom providers in the main and they all have to rely on BT to provide the wholesale bandwidth except in a few urban areas. The result is that they are not able to put in place the warehouses and OFCOM will not allow BT the monopoly of building them. So we end up where we are to day.
If only people had listened to Lord Young in the early 90s when he was at C&W, the killer app for networks was always gong to be video and the merging of telecoms networks with entertainment was always going to give the telecoms players a chance to pull revenue through content unfortunately the delays in its arrival meant everyone went to commodity pricing for something that will never be a true commodity.